Glass gob drop guide funnel assembly

ABSTRACT

A graphite funnel inserted into a metal funnel support sleeve guides hot glass gobs from a furnace to the glass blowing mold. The graphite insert is adjustable by set screws and is easily repositioned. The graphite insert has an outer diameter slightly less than the metal retainer to allow ambient air to pass upwardly past it.

This application is a division of application Ser. No. 07/953,726, filedSep. 29, 1992, U.S. Pat. No. 5,394,910, which is continuation in part ofapplication Ser. No. 07/937,343, filed on Aug. 27, 1992, abandoned. Bothof these prior filed applications are incorporated in their entiretyherein by reference.

FIELD OF THE INVENTION

This invention relates to methods of making blown glass articles,particularly to methods of apportioning molten glass for making blownglass articles. More particularly this invention relates to guidefunnels for glass gobs.

BACKGROUND

Machines make glass bottles by placing a portion of molten glass, or a"gob" of glass, into a mold and pressing and/or blowing air or other gasinto the center of the gob. This causes the hot glass to expand to theside of the mold and take on the shape of the mold. Before the glass isintroduced into and formed in the mold, the raw glass must first beheated in a furnace normally located above the mold. The hot glass gobis conditioned (or cooled slightly) in a fore-hearth to a temperatureconsistent with a glass viscosity suitable for the forming operation.The glass is then dropped down through the fore-hearth and into the moldfor forming, e.g., blowing. The fore-hearth extrudes hot molten glassthat is cut into substantially uniformly weighted, but non- sphericallyshaped glass gobs produced intermittently.

The glass gobs drop from the fore-hearth into a guide funnel, whichkeeps the gobs oriented and may shape them to properly engage a gobscoop and the mold. The gobs typically fall a distance ranging fromabout 6 to 24 inches (15.24 to 60.96 cm). The gobs have a tendency totip as they fall and it is beneficial to have a funnel means ofcorrecting their attitude before entering a gob scoop and placement intoa blank mold. After passing through the funnel and the gob scoop, thegobs are typically directed to placement into one of a plurality ofmolds by means of troughs. After placement into a mold, the gobs areblown or otherwise formed into a product shape.

The funnel must withstand an extreme environment. The interior mustcontact intermittent molten glass gobs that can range in temperature upto about 2300° F. (1260° C.) for typical glass compositions, up to about2732° F. (1500° C.) or more for high silica content glasses. Typically,the (softening) temperature of the glass gobs ranges from about 2000° to2200° F. (1093° to 1204° C.), but may be as low as about 1500° F. (816°C.).

Glass gobs are typically cylindrical in form and sheared from a flow ofmolten glass as it exits from the fore-hearth, the glass gobs havingweights ranging from about 1/4 to 31/2 pounds (0.113 to 1.59 kg), butmore typically in the range from about 1/2 to 11/2 pounds (0.227 to0.680 kg). The gob's representative diameter can range from about 3/4 to2 inches (1.91 to 5.08 cm). The number of gobs passing through a givenfunnel typically ranges from 80-150 per minute or 4800-9000 per hour.These frequencies and extreme gob temperatures, sizes, weights, anddropping energies of the gobs are interspersed with exposure to ambientair temperatures ranging up to about 200° F. (93.3° C.), typically about150° F. (65.6° C.) because of the proximity of the furnace.

The kinetic energy of the gobs being dropped, when combined with theintermittent high temperature shock of the gobs, tends to damage theinterior of almost any funnel. Materials that can withstand continuousexposure to the glass gob temperatures tend to be brittle and subject tocracking when exposed to thermal and structural shock. Even if crackingor other failures are avoided, cooling of the funnel at the exteriorsurface (or at internal cooling passages) is needed to maintain thestructural integrity of many funnel materials of construction at thesehigh temperature conditions. Presently, metallic funnels must be cooledwell below the temperatures of the glass gobs. This is typicallyaccomplished by circulating large volumes of water in external Jackets.

Some recently developed funnels are composed of carbon fitted for forcedair cooling instead of water. The carbon funnels have been machined witha plurality of baffles or fins to achieve sufficient cooling usingforced air. The baffles or fins protrude into the forced air stream atleast about 1/8 inch (0.318 cm).

However, these funnels erode in this harsh environment. Typically, theerosion is not equally distributed around the circumference of thefunnel, but tends to be in one angular location. The angular location ofmaximum erosion is primarily a function of funnel location andorientation with respect to the fore-hearth. These location specificfailure modes have resulted in a shortened useful life and costlyreplacement of funnels.

It would be advantageous to have a funnel that did not need to bereplaced as frequently and that did not need to be cooled by fluidsdriven by mechanical means and/or require the complicated machinedcooling passage/baffle/fin shapes required by forced air cooling.

SUMMARY OF THE INVENTION

In this invention, a metal funnel support sleeve holds a graphite funnelliner that guides hot glass gobs from a fore-hearth to a glass gob scoopor other device leading to a forming device. The operator can easilyreposition and replace the liner. The bottom of the graphite liner hasan outside diameter less than the inside diameter of the metal supportsleeve to allow natural circulation of air to pass upwardly past thegraphite insert.

More specifically, an aspect of this invention is the non-protrudingexterior shape of the graphite glass gob liner and the substantial lackof forced fluid cooling of the exterior shape. The liner exteriorcomprises a substantially tube-shaped monolithic piece of graphitehaving: a) a cylindrical top collar portion, the underside of the collarterminating in a bearing ledge; and b) a generally cylindrical bottomportion having an outside diameter less than the outside diameter of thecollar portion. The outermost or exterior surface of the liner portions(i.e., the surface at the outside diameter of each portion) does notneed to be cooled by forced circulation of water and/or air stream(s)and also does not require protruding fins or baffles into the coolingstream(s).

A second aspect of this graphite glass gob funnel assembly is an outercylindrical support sleeve. The graphite funnel is disposed within thesupport sleeve. The support sleeve has an outside diameter similar tothe collar portion of the graphite liner. The ledge of the collarportion rests on the support sleeve portion in a substantially verticalorientation.

Another aspect of this invention is the interior surface of the graphitefunnel. The interior funnel surface forms an interior passagewaypenetrating the liner and narrowing from top, defined by a top enddiameter greater than at a bottom end internal diameter, and acylindrical interior bottom portion. The bottom portion can be cut-off,radially repositioned, and/or laterally repositioned to direct glassgobs from a furnace to one or more variable location molds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cut away perspective drawing of the glass guidingfunnel assembly of this invention.

FIG. 2 is an elevational view of the glass gob funnel liner of thisinvention.

FIG. 3 is an elevational view of the outer support sleeve of the glassgob funnel assembly of this invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a glass gob guiding funnel assembly 10 embodimentof the invention is shown. The funnel assembly 10 includes a funnelliner 12 and a support sleeve 14. A collar 16 of the funnel liner 12terminates in a bearing ledge 18 that is retained on the upper edge ofthe support sleeve 14. Glass gobs fall into the funnel liner 12 from afore-hearth (located above, not shown) into a receiving orifice 26 thatintroduces the glass gobs into a conical well interior surface 28 to bedirected to a mold (located below, not shown) through a delivery orifice32.

The outside diameter of the collar 16 and outside diameter of thesupport sleeve 14 are shown to be approximately equal, but differencesin the outside diameters of these components are also possible. Thepreferred embodiment has an outside collar diameter between 95% and 110%of the outside diameter of the support sleeve, assuring that the funnelliner 12 can be supported by the support sleeve 14. The similar outsidediameters also tend to simplify space allocation for the funnel assembly10 and avoid protrusions likely to cause handling damage. Other,substantially non-protruding exterior shapes for the funnel liner 12would accomplish a similar purpose and are also possible.

The exterior length of the substantially cylindrical collar 16 is afunction of the locations of the fore-hearth, the mold(s), and theassociated machinery. The exterior length of the collar 16 is also afunction of the material strength and thermal characteristics of thecollar 16. The length of the collar 16 must extend sufficiently towardsthe fore-hearth to reliably encompass the dropping glass gobs,distribute the supporting loads from the bearing ledge or surface 18,and allow grasping of the funnel liner 12 for removal or reorientation.However, the collar length must not be so large so as to present anobstruction, prevent easy replacement and handling, or interfere withthe molding operation. For the preferred funnel liner material ofGLASSMATE-SR®, supplied by Poco Graphite, Inc., the collar lengths mayrange from as little as about 1/2 to as much as 2.0 inches (1.27 to 5.08cm), but more preferably ranges from about 1 to 2 inches (2.54 to 5.08cm) for a nominal outside diameter of 27/8 inches (7.303 cm). For alarger nominal outside collar diameter of 4 inches (10.16 cm), thecollar length may change, but is still expected to range from about 1/2to 2 inches (1.27 to 5.08 cm). Another way of expressing these collardimensions is that the ratio of the length of the collar to the outsidediameter ranges from about 0.125 to 0.70 for the preferred materials ofconstruction.

The collar 16 (and all of the funnel liner 12) is preferably composed ofa GLASSMATE-SR® graphite material supplied by Poco Graphite, Inc.located in Decatur, Tex. Table 1 provides typical physical properties ofthe preferred GLASSMATE-SR® material. This material, combined with theconical interior and tubular exterior shape of funnel liner 12, providesa smooth surface and good directional control without scratching theglass gobs. The material and the design also provide good resistance tothe harsh temperature and erosive environment without the need forforced air cooling or exterior-protruding heat exchange surfaces such asfins or baffles. Alternative materials of construction includeGLASSMATE® and GLASSMATE-LT®, also supplied by Poco Graphite Inc.

A key physical property of the preferred GLASSMATE-SR® material is arelatively high thermal conductivity of at least 70 BTU-ft/ft² -hr-F,even at elevated temperatures. In contrast, carbon and graphitematerials for high temperature service only have an average thermalconductivity of 8 BTU-ft/ft² -hr-°F. (per Chemical Engineers' Handbook,by Perry and Chilton, Fifth Edition, 1973). In addition, many graphitematerials are anisotropic, having even lower thermal conductivities insome directions. A thermal conductivity of at least 50 BTU-ft/ft²-hr-°F., preferably at least 60 BTU-ft/ft² -hr-°F., for the funnel linermaterials of construction minimizes hot spots and avoids the need forforced air or water cooling with fins or baffles. The external lengthand outer surface diameter of collar 16 (when composed of high thermalconductivity graphite) provide a sufficient surface area for cooling bynatural convection of the ambient air.

                  TABLE 1    ______________________________________    TYPICAL ROOM TEMP.    PHYSICAL PROPERTIES OF GLASSMATE-SR ®    Property (at room temp) Typical Value    ______________________________________    Density (g/cc)          1.82    Hardness (Shore Scleroscope)                            65    Flexural Strength                 (psi)          9,000                 (Kg/cm.sup.2)  633    Compressive Strength                 (psi)          16,000                 (Kg/cm.sup.2)  1,125    Thermal Conductivity                 (BTU-ft/ft.sup.2 -hr-°F.)                                76                 (Cal-cm/cm.sup.2 -sec-°C.)                                0.27    Coefficient of Thermal Expansion                            8.2    ______________________________________    TYPICAL HIGH TEMP.    PHYSICAL PROPERTIES OF GLASSMATE ®    Property at 572° F. (300° C.)                            Typical Value    ______________________________________    Density (g/cc)          1.8    Hardness (Shore Scleroscope)                            65    Flexural Strength                 (psi)          9,000                 (Kg/cm.sup.2)  633    Compressive Strength                 (psi)          16,000                 (Kg/cm.sup.2)  1,125    Thermal Conductivity                 (BTU-ft/ft.sup.2 -hr-°F.)                                70                 (Cal-cm/cm.sup.2 -sec-°C.)                                0.25    Coefficient of Thermal Expansion                            8.1    ______________________________________

Another key property of GLASSMATE-SR® is a flexural strength of 9,000psi which is relatively high for graphite. A flexural strength of atleast 8,000 psi, preferably at least 8,800 psi, allows the funnel liner12 to be easily handled without damage, repositioned, and secured atdifferent positions. Its strength also allows the funnel liner to bedeformed somewhat to adjust the location of a discharge orifice 32 withrespect to the fore-hearth and/or mold, e.g., the funnel liner shape canbe distorted without cracking.

The flexural strength of GLASSMATE-SR® allows the funnel liner 12,including the supporting collar 16, to be supported over a small area ofthe substantially single piece or monolithic construction. Instead of abroad area of support to minimize flexural stresses, a small ledge 18area on the collar 16 is sufficient to support even a deformed funnelliner 12.

Another key property of GLASSMATE-SR® is its high density (andassociated low porosity) of about 1.82 g/cc. A liner material density ofat least about 1.77 g/cc, preferably at least about 1.8 g/cc, results ina smooth, hard surface on the interior of the funnel liner 12 aftermachining so that the deflected glass gobs can be formed without damage(after they enter the mold).

These combined graphite properties and the repositionable design resultin undamaged gob delivery, low erosion rates, and infrequentrepositioning required. For gob delivery rates of at least about 4800per hour, repositioning is expected to be required no more than abouttwo times per year, preferably less than about once per year.

The inside surface of collar 16 of the funnel liner 12 shown in FIG. 1is a right circular cone frustrum, conically narrowing downward. Theglass gobs fall in direction "A" towards the funnel liner 12. In orderto control the velocity of the gobs and/or cool the interior of thefunnel, a flow of air (or another fluid) may also be generally directedin direction "A" (for acceleration of the gobs) or an opposite direction(for deceleration). The cone angle of the funnel liner can vary widely,but is generally no more than 10 degrees and typically in the range fromabout 6 to 8 degrees. This angle provides a smooth transition betweenthe entry and outlet of the funnel liner.

The smooth and downwardly narrowing internal geometry is primarily afunction of the length of the funnel liner 12. A cone extending most ofthe length of funnel 12 provides a greater interior contact surface andtime for the dropping glass gob to conform to the location and diameterof the exit orifice 32.

The geometry of the inlet orifice 26 of collar 16 is primarily afunction of the location and size of the glass gobs dropping from thefore-hearth. If a flow of air of other fluid in direction "A" is used toaccelerate glass gobs, the inlet orifice size would also have toaccommodate this flow. Although the inlet orifice 26 size can varywidely, expected circular orifices are expected to range from about 2.5to 3.75 inches (6.35 to 9.525 cm) in diameter for nominal 11/2 pound(0.68 kg) glass gobs having a substantially cylindrical diameter in arange from about 3/4 to 2 inches (1.91 to 5.08 cm). Alternativegeometries for the inlet orifice 26 may include elliptical, rectangular,and triangular shapes.

Alternative funnel interior surfaces may include a substantiallystraight upper tubular portion (prior to a conical narrowing), anarrowing pyramidal shape (e.g., extending from a triangular orifice)instead of a truncated cone, or a segment of a paraboloid of revolutioninstead of the cone. In any of these alternative geometries, a majordimension of the inlet orifice 26 is expected to be larger than acorresponding dimension of the discharge orifice 32 of the funnel liner12.

In the preferred embodiment shown, the funnel liner 12 includes acylindrical section 20 below the collar 16 that fits within acorresponding portion of the support sleeve 14 over a relatively shortlength. The typically metallic support sleeve 14 not only supports thefunnel liner 12 (at bearing ledge 18), but shields and protects themajority of the exterior surface of the graphite funnel liner fromdamage by moving objects. The outer diameter of the funnel liner'scylindrical section 20 is smaller than the outer diameter of the collar16 by an amount equal to twice the thickness of a narrow ledge 18. Thelength may be longer if increased lateral loads and support is needed,e.g., if the funnel axis is non-vertical. If the cylindrical section 20is in contact with the support sleeve 14, the contacted support sleeve14 portion prevents full exposure of the outer surface of thecylindrical section 20 directly to the ambient air, precludingunobstructed natural convection heat transfer from the funnel liner 12at this surface. The obstruction tends to increase the temperature ofthe funnel liner 12 at this surface. However, the relatively highthermal conductivity of the funnel liner material, natural convectioncooling at the exterior surface, and the thermal contact with thecylindrical section 20 tends to dissipate any increased temperature atthis surface.

In order to maintain the funnel liner 12 centered on bearing ledge 18and circumferential thermal contact between the support sleeve 14 andthe cylindrical section 20, the outer diameter of the cylindricalsection 20 preferred embodiment mates with the inner diameter of thesupport sleeve 14. This can be achieved by roundness and dimensionaltolerances on these diameters to assure an interference (or force) fit,press fit, or sliding fit.

If a variable and resettable positioning of the funnel liner's collar 16with respect to the support sleeve 14 is desired, the outer diameter ofthe cylindrical section 20 is dimensioned to be less than the insidediameter of the support sleeve 14. Centering, if required, is obtainedby positioning the resettable funnel liner 12 within the support sleeve14 using set screws 34.

Below the relatively short cylindrical section 20 is a conical narrowingportion 22 that provides a bottom gap 24 between the support sleeve 14and the bottom portions of funnel liner 12. The bottom gap 24 allowsambient air to enter from below and cool the funnel liner by naturalconvection, similar to the natural convection cooling of collar 16previously described. Again, this cooling is in the absence of anysubstantial number or extent of protrusions such as fins or baffles. Toaid in the natural circulation of the (heated) air in bottom gap 24after the air contacts the funnel liner 12, apertures 38 have beenprovided in the support sleeve 14. Although no theoretical limitationexists for the width of bottom gap 24, an average gap width of at leastabout 1/8 of an inch (3.175 mm) along a majority of the length of thebottom gap 24 is expected to be needed for adequate natural convectioncooling, preferably at least about 5/32 of an inch (3.97 mm).

The conical narrowing portion 22 terminates in a straight guidingportion or tube portion 30 that delivers the glass gobs through adelivery orifice 32 to a gob scoop leading to molds. The length of thetube portion 30 can be varied to accommodate various fore-hearth to molddistances, allowing the gob scoop to be more easily positioned withrespect to its proximity to the fore-hearth. Overall length of thefunnel assembly 10 would therefore vary with the length of the tubeportion 30, preferably ranging from about 6 to 20 inches (15.24 to 50.8cm).

Variations in fore-hearth to gob scoop distances can also beaccommodated by removing a portion of the variable length tube portion30. Even if the tube portion 30 is mostly removed, the conical shape ismaintained since the internal passageway of this portion is cylindrical.

Because the gob scoop distance variations can be accommodated by changesin tube portion 30 length changes, the funnel assembly can bemodularized with many common portions. For example, four modular stylesof funnel assemblies, having an overall length of about 6, 10, 15, and20 inches (15.24, 25.4, 38.1, and 50.8 cm) respectively, couldaccommodate typical mold distance variations. Each of these assembliescould have a common collar, ledge, cylindrical and narrowing portionswith similar internal passageways. Each of these length sizes could alsobe made in, for example, three different internal passageway geometriesand outer diameters. Modular construction would standardize fabrication,minimize cost, and allow the components to be cut to a particular sizemeeting a specific customer's mold size and distance requirements.

An operator can adjust the radial position of the funnel liner 12 anddeflect the delivery of the glass gobs to the molds by a series of setscrews 34 mounted at different distances above the bottom of the supportsleeve 14 radially around the support sleeve 12. Especially if thelongitudinal axis of funnel liner 12 is non-vertical or deformed by theset screws 34, the interior of the funnel liner 12 may have uneven wearcaused by the glass gobs impacting one spot repeatedly as the glass gobspass to the mold.

To correct any unevenness in wear, the collar 16 has a series of grooves36 spaced around the bearing ledge 18 of the collar 16. These set thefunnel liner 12 in one specific circumferential and radial orientationwith respect to the support sleeve. As one portion of the interior ofthe funnel liner 12 becomes worn, the set screws 36 can be retracted andthe funnel liner 12 rotated. The grooves 36 engage a ridge member orother protrusion 46 mounted on the top of the support sleeve 14. It willof course be realized that the number of grooves and protrusions couldbe varied. As the interior of the funnel liner 12 starts to show unduewear at any orientation, the operator can periodically release, rotate,and resecure the funnel liner 12. Periods between rotations would varywith each application, but are expected to be in the range from about 26to 50 weeks, more typically 30 to 40 weeks. In this manner, the unevenwear caused by the passage of the hot gobs of glass in the interior ofthe funnel liner 12 is evened out.

Alternatively, the support sleeve 14 could have grooves and the funnelliner 12 have an engaging ridge. The engaging ridge of the funnel linerwould not necessarily be composed of graphite material, but may be a pin(or a plurality of pins) imbedded in the graphite. Each of the supportsleeve's grooves would mate with the imbedded pin in one position,allowing the funnel to be rotated to other positions where anothergroove would mate with the imbedded pin.

The passage of hot glass gobs also heats the funnel liner 12, especiallyat the narrowest portions, to a high temperature. Funnel liner 12temperatures at the interior surface as high as the glass gobsthemselves (e.g., 2200° F. or 1204° C.) are possible, but thesetemperatures can weaken and/or cause thermal gradients in the funnelliner 12. To reduce thermal gradients, only ambient air directly coolsthe majority of the exterior surface of funnel liner 12. The ambient airflows around the outer diameter of collar 16 and around the straightguiding tube and narrowing sections 30 and 22 of liner 12 in the bottomgap or space 24. The space 24 is relatively unimpeded by baffles or finsand natural convection heating of the air next to the graphite funnelliner 12 causes the heated air to rise and flow through the apertures38. The apertures 38 allow hot air within the support sleeve 14 to passto the outside and be replaced by cooler ambient air from below. Averageair velocity across the funnel surface due to this natural convection isexpected to be less than about 7 feet per second (2.13 meters/see),preferably less than about 2 feet per second (0.61 meters/sec).

The use of ambient air (instead of forced air or water cooling) and theabsence of funnel liner fins or baffles, increases exterior surfacetemperatures of the funnel liner 12 and decreases thermal gradientswithin the funnel liner 12. The increased funnel temperature anddecreased thermal gradients also tend to minimize thermal gradients inthe glass gobs, reducing damage and cracking tendencies in both themolded glass product and the funnel liner 12.

Mounting flange 40 attaches the support sleeve 14 to a machine (notshown) or related equipment that molds the glass gobs into bottles (orother products). The mounting flange 40 secures the support sleeve 14 tothe molding machine or other equipment. The support sleeve 14 is noteroded by the glass gobs and need not be replaced once it is assembled;only the funnel liner 12 need be replaced because of erosion.

After retracting the set screws 34, an operator can easily slip thefunnel liner 12 into and out of the support sleeve 14 without unduedisruption of the production of bottles or other formed glass product.The funnel assembly 10 can generally substitute for currently usedforced air or water cooled funnels, and can be used as a full retrofitor replacement part for those funnels.

Referring to FIG. 2, the funnel liner 12 is a mostly cylindrical,substantially monolithic graphite construction having, at its top, acollar 16 having a bearing surface 18 that is engagable with the topedge of the support sleeve 14 (see FIG. 3) and a top surface including areceiving orifice 26 that leads to the interior, conical well surface ofthe funnel liner 12. The collar 16 has a plurality of grooves 36 thatcan engage the ridge member 46 mounted on support sleeve 14 (see FIG.3). The overall height of the funnel liner 12 is typically greater than4.0 times the dimension of the outside diameter of the collar 16 of thefunnel liner. The bottom of the collar 16 ends with a small bearingledge 18 having an inside diameter that is typically between 2% and 10%less than the outside diameter of the collar and, preferably, hasgrooves 36 cut across the entire width of ledge 18. The difference indiameter and ledge-width grooves allow off-center placement of thefunnel liner 12 in the support sleeve 14. The depth of grooves 36 isexpected to range from about 0.188 to 0.250 inches (0.478 to 0.635 cm)to allow significant non-parallel axial placement of the funnel liner 12on the support sleeve 14.

The cylindrical section 20 extends beneath the collar 16 for a shortdistance. The outer surface of the cylindrical section 20 is cylindricaland may or may not be in contact with the inner surface of the supportsleeve 14 as shown. A thermal insulating material can also be sandwichedbetween the support sleeve and funnel liner surfaces if the temperatureof the contacting support sleeve 14 becomes excessive. In the preferredembodiment, the short length of the cylindrical section 20 can provide abearing surface which, in combination with the close tolerance fit,supports and centers the funnel liner 12. The length of the cylindricalbearing surface extends below the bearing ledge 18 and, preferably, isbetween 0.5 and 2.0 times the width of the bearing ledge 18. The bearingsupport at this interface would be in addition to any support andcentering provided by the set screws 36.

In an alternative embodiment, the set screws 36 are deleted. A closetolerance fit between the outside surface of cylindrical section 20 andsupport sleeve 14 centers and retains the funnel liner 12 without theneed for set screws 36. Off center placement and support can also beachieved by shims placed between the cylindrical section 20 and thesupport sleeve 14. If the funnel liner 12 must be deformed to provide acurved path from the fore-hearth to the gob scoop without set screws 34,the deformation may be accomplished by other means, for example, a gobscoop protrusion deforming the funnel liner 12.

Returning to the embodiment shown in FIG. 2, below the cylindricalsection 20 is a conical narrowing section 22 that results in the bottomgap 24 forming between the support sleeve 14 and the funnel liner 12 asthe outside diameter decreases. Since the inside and outside surfaces ofthe conical narrowing section 22 are conical, the narrowing section 22also minimizes the thickness of the funnel liner 12 so that it may moreeasily be deformed, e.g., by the set screws 34.

Another alternative embodiment deletes the cylindrical section 20,having the collar 16 attached to the narrowing section 22. Contactbetween the support sleeve 14 and the funnel liner 12, if required,would be reduced to a circumferential line contact between the conicalnarrowing section 22 and the support sleeve 14. If additional contactarea is needed, wedges could be used.

Still another alternative embodiment deletes the conical narrowingsection 22 and the cylindrical section 20, the funnel liner having onlyan alternative collar section and an alternative guiding tube, bothhaving a substantially cylindrical exterior surface. The outsidediameter of the alternative guiding tube portion would be less than theinside diameter of the support sleeve 14, producing an annular spacesimilar to the bottom gap or space 24. The inside surface of thealternative funnel liner would also be a smoothly narrowing geometrystarting from an inlet orifice to an outlet orifice.

Still another alternative embodiment supports a funnel liner having aconical outside surface mating with a support sleeve having an insideconical supporting surface in place of the substantially horizontal topsupporting ledge 18. Ridge members and grooves, e.g., similar to thoseshown in FIG. 1, could also be placed in the mating conical surfaces toallow periodic repositioning.

In the preferred embodiment shown in FIG. 2, the bottom surface ofguiding tube 30 includes a circular delivery orifice or bottom aperture32. The bottom aperture 32 is placed and sized to delivery the glassgobs to the gob scoop or other formable glass handling apparatus. If aflow of air is used to further accelerate or decelerate the glass gobsthrough the funnel, the shape of the bottom aperture 32 is alteredcomensurately. The accelerated (direction A on FIG. 1) or deceleratedglass gobs pass from the receiving orifice 26 to the delivery orifice 32through the conical well 28. The inlet orifice 26 and conical well 28define the initial internal passageway that receives the hot glass gobsfrom the fore-hearth and guides them to the final straight guiding tube30 portion that delivers the glass gobs to the gob scoop or other moldrelated apparatus.

The inside surfaces of both the conical well 28 and the straight guidingtube 30 are smooth and allow unobstructed passage of the glass gobs fromthe fore-hearth to the mold. Because of the high density and lowfriction properties of GLASSMATE-SR®, the inside surfaces of the funnelliner 12 can have a relatively rough surface finish of about 250 in. rms(6.35 microns, rms) without significant damage to some molded glassproducts, but a surface roughness in the range of about 63 to 125 μin.rms (1.60 to 3.18 microns, rms) is more typical.

The funnel assembly 10 is typically mounted substantially in a verticalorientation to facilitate the free passage of glass gobs. Verticalmounting allows the baring ledge 18 to support the funnel liner 12 inthe support sleeve 14 without further attachment means to secure thefunnel liner 12 to the support sleeve 14. The cylindrical section 20adds stability to the assembled funnel by allowing further support ofthe funnel liner 12 inside the support sleeve 14.

The funnel liner 12 extends downwardly into the support sleeve 14 andthe location of the bottom aperture 32 delivering the glass gobs can bechanged by adjusting the set screws 34 (shown in FIGS. 1 and 3) providedat the lower portion of the support sleeve 14. The delivery location ofthe glass gobs to the molds is adjusted by rotating the set screws 34 inthreaded holes located in the support sleeve 14. Preferably, 1/4 inch(6.35 mm) nominal diameter set screws are arranged circumferentiallyaround the support sleeve 14 at different distances from the bottom ofthe support sleeve 14. The placement of set screws 34 around thecircumference allows radial displacement of the delivery aperture 32.The placement of set screws 34 at different points along the length ofthe funnel assembly 10 allows access and bottom cut-off capability fordifferent mold dimensions and fore-hearth to mold distances. Set screws34 are preferably placed every 60 to 120 degrees around the funnelassembly 10 and along a portion of the length of the straight guidingtube 30 every 1 to 2 inches (2.54 to 5.08 cm).

Referring to FIG. 3, the support sleeve 14 of the funnel assembly 10includes a hollow cylindrical tube 42 and a mounting flange 40. Commonstructural materials of construction may be used, such as plates orrolled sheet steel or tubes of low carbon steel or aluminum tubes. Theinside diameter of the hollow cylindrical tube 42 is substantially thesame as or slightly less than the outside diameter of the cylindricalsection 20 of the funnel liner 12 if centering, lateral support, and/orcontact is desired at this surface. Set screws 34 allow the operator toaccurately position the delivery orifice 32 of the inserted funnel liner12 over or into the mold even if the funnel liner 12 is firmly supportedat the cylindrical section 20 and ledge 18.

The top edge of the support sleeve 14 includes an attached ridge member46 that engages at least one of the grooves 36 in the funnel liner 12.The ridge member 46 is attached to the support sleeve 14 by screw 48 orsimilar conventional means, or it can be machined as a part of the topof the support sleeve 14.

A series of apertures 38, generally sized between 0.5 and 0.05 times thediameter of the cylindrical tube 42, allow hot air generated fromcontacting the funnel liner 12 to escape. The apertures 38 are locatedcircumferentially around and along the length of the support sleeve 14,especially where the guiding tube 30 portion of the inserted funnelliner 12 in the assembled funnel assembly 10 normally is. Preferably,the apertures are about 3/4 inch (1.905 cm) in diameter and spaced aboutevery 1 inch (2.54 cm) along the length and about every 90 degreesaround the circumference. Alternative aperture geometry and spacing arealso possible, such as more closely spaced rectangular slots.

The funnel liner 12 can be rotated to allow more even wear of theliner's inside surfaces. When the funnel liner 12 is rotated, ridgemember 46 engages one of the plurality of engagement slots on the funnelliner 12, thereby fixing the funnel liner 12 in a particular renditiondetermined by the user of the funnel assembly 10.

In the preferred embodiment of this invention, the collar has a seriesof grooves that are spaced sixty degrees apart and radially set thefunnel liner in one circumferential orientation. If the funnel starts toshow undue wear at any orientation, then the funnel liner can be rotatedand the wear can be spaced over the entire internal area of the funnelliner.

Still other alternative embodiments of the invention are possible. Forexample: a gob scoop and/or trough composed of GLASSMATE-SR® havingexterior surfaces (i.e., surfaces not contacting glass gobs)subtantially in the absence of fins, baffles, and/or mechanicallyinduced fluid flow: a funnel having a composite material ofconstruction, such as a metal tubular portion substantially sandwichedwith a graphite portion, to combine the separate functions of the linerand support sleeve; a modified funnel-like assembly used forintermittent extruding or drawing operations, e.g., a funnel and/or aplug assembly having an outside liner and a support for drawing glasstubing; a mold liner, e.g., plugging the delivery orifice of the funneland splitting the assembly to create a conical mold; and a replaceableor detachable bottom tube portion attached to a narrowing portion 22instead of the monolithic tube portion 30 that can be cut-off. In all ofthese alternative embodiments, the materials and shapes would allow thehandling of hot glass subtantially in the absence of mechanically drivencooling fluid flows across non-glass contacting surfaces and/orsubtantially in the absence of fins, baffles, or other coolingprotrusion at these surfaces.

Although this invention has been primarily described by references toembodiments thereof, it is evident that the foregoing descriptionsuggests many alternatives, modifications, and variations to thoseskilled in the art. Accordingly, the spirit and scope of the appendedclaims are intended to embrace within the invention all suchalternatives, modifications, and variations.

What is claimed is:
 1. A graphite glass gob funnel assemblycomprising:an outer cylindrical support sleeve having an outer diameterat an upper surface; and an inner substantially tube shaped monolithicpiece of graphite having a tubular body resting on the upper surface ofthe support sleeve, wherein said tubular body is rotativelyrepositionable on said sleeve between a plurality of stationarypositions and assembly includes means for fixedly receiving said tubularbody in each of said positions with respect to said support sleeve. 2.The glass gob funnel assembly of claim 1 wherein the outer supportsleeve has a ridge member on its top edge.
 3. The glass gob funnel ofclaim 2 wherein the graphite liner has a plurality of grooves in thecollar portion that engage the ridges of the liner.
 4. The glass gobassembly of claim 2 wherein the support sleeve and the funnel liner forma gap for at least part of the distance taken by the liner within thesupport sleeve.
 5. The glass gob assembly of claim 4 wherein the supportsleeve defines a series of apertures located at the gap to allow the hotair generated by the passage of glass gobs to escape from the gap.
 6. Anapparatus for handling formable glass comprising:an internal passagewayextending from an entry to a second location, wherein said passageway iscapable of handling said formable glass from said entry location to saidsecond location distal from said entry location; an exterior surfacesubstantially free of cooling protrusions; and wherein said apparatus issubstantially composed of a material capable of handling said formableglass in the absence of a cooling fluid flow driven by mechanical meansand wherein said apparatus is also capable of being supported in aplurality of adjustable positions.
 7. The apparatus claimed in claim 6wherein said passageway narrows in a substantially continuous mannerfrom a location proximate to said entry location to said secondlocation, forming a funnel.
 8. The funnel claimed in claim 7 whereinsaid funnel is substantially composed of a material having a thermalconductivity of at least 50 BTU-ft/ft² -hr-°F.
 9. The funnel claimed inclaim 8 wherein said funnel is assemblable into a funnel assembly whichalso comprises:means for deforming the shape of said passageway; andmeans for supporting said funnel.
 10. A funnel comprising:asubstantially tubular body defined on the exterior by (a) a top collarportion having an outer diameter and a length, said top collar portionterminating at the bottom of its length in a ledge, and (b) a bottomsubstantially conical portion; said body substantially composed ofgraphite and further defining an interior surface forming a tubularpassageway from the top end of the top collar portion to the bottom endof the bottom conical portion defined by an interior diameter greater atthe top end than at the bottom end; and means for rotativelyrepositioning and fixedly securing said tubular body in a plurality ofstationary positions with respect to a support for said tubular body.11. The funnel of claim 10 which also comprises:a support for saidtubular body supporting said tubular body at said ledge; and means forreleasing said means for securing.
 12. The funnel of claim 11 which alsocomprises means for resecuring said tubular body in a position withrespect to said support.
 13. The funnel assembly of claim 12 whereinsaid means for retaining comprises set screws.
 14. The process ofmolding glass which comprises:heating glass gobs in a furnace; releasingat least a portion of said heated glass gobs from said furnace to afunnel; discharging said heated glass gobs from said funnel to a moldingmachine wherein said funnel is fixedly secured against rotationalmovement in a position with respect to said molding machine; androtatably repositioning said funnel to one of a plurality of positionswith respect to said molding machine after said discharging step.